cal/cal/LaFortune1.cal

{ RCSid $Id: LaFortune1.cal,v 1.1 2014/03/18 16:16:37 greg Exp $ }
{ LaFortune reflectance model with one lobe }

        { Sample parameters (change these) }
rho_d : 0.136465483630983;
rho_s : 0.144594472775860;
Cx : -0.605122636448704;
Cy : -0.664960041454502;
Cz : 0.586571000768196;
n : 29.629194300125050;

                        { Useful functions }
abs(x) : if(x, x, -x);
noneg(x) : if(x, x, 0);

        { Normalization factor based on parameters }
snf : (n+2)/(2*PI*max(abs(Cx),abs(Cy),abs(Cz))^n);

{ Note that we assume i and o vectors are normalized, both pointing away }

lafortune(ix,iy,iz,ox,oy,oz) : if( -iz*oz, 0,
                rho_d/PI + rho_s*snf*noneg(Cx*ix*ox + Cy*iy*oy + Cz*iz*oz)^n );
Revision:	1.2
Committed:	Mon Jun 10 13:56:52 2019 UTC (5 years ago) by greg
Branch:	MAIN
CVS Tags:	rad5R4, rad5R3, HEAD
Changes since 1.1:	+2 -3 lines
Log Message:	Added max() and min() as .cal library functions
#	Content
1	{ RCSid $Id: LaFortune1.cal,v 1.1 2014/03/18 16:16:37 greg Exp $ }
2	{ LaFortune reflectance model with one lobe }
3
4	{ Sample parameters (change these) }
5	rho_d : 0.136465483630983;
6	rho_s : 0.144594472775860;
7	Cx : -0.605122636448704;
8	Cy : -0.664960041454502;
9	Cz : 0.586571000768196;
10	n : 29.629194300125050;
11
12	{ Useful functions }
13	abs(x) : if(x, x, -x);
14	noneg(x) : if(x, x, 0);
15
16	{ Normalization factor based on parameters }
17	snf : (n+2)/(2PImax(abs(Cx),abs(Cy),abs(Cz))^n);
18
19	{ Note that we assume i and o vectors are normalized, both pointing away }
20
21	lafortune(ix,iy,iz,ox,oy,oz) : if( -iz*oz, 0,
22	rho_d/PI + rho_ssnfnoneg(Cxixox + Cyiyoy + Czizoz)^n );